Cam operated multiple contact switch



y 1966 c. A. WOODCOCK 3,250,881

CAM OPERATED MULTIPLE CONTACT SWITCH Filed Aug. 20, 1964 a mu /6 L i F/Ci 22 United States Patent M 3,259,881 CAM OPERATED MULTRPLE CONTACT SWITCH Charles A. Woodcock, Springfield, Ill., assignor to Stewart- Warner Corporation, Chicago, .Ill., a corporation of Virginia Filed Aug. 20, 1964, Ser. No. 390,796 9 Claims. (Cl. 200-153) This invention relates in general to plunger operated switches and more particularly to a plunger operated multiple pole switch for use with automobile doors or the like.

Switches of the type that are generally utilized for autotomatic operation in response to either opening or closing of a door must be necessarily of rugged durable construction and in addition the economics of the industry necessitate an extremely simple and economical design.

It is therefore a primary object of the present invention to provide an improved and more economical switch construction.

In addition with the expansion of facilities usually provided with automobiles it is desirable that the switches actuated by an automobile door for example be adapted to simultaneously conrtol a number of different circuits. These switches are usually actuated by a spring biased plunger, which is adapted to be moved by a return spring intoone position on opening the door or other closure and into another position on closure of the door to operate a number of spring or contact blades in each position.

It is, therefore, another object of the present invention to provide an improved multiple contact switch of the type having a plunger adapted to be operated by an automobile door or other mechanism.

Since the pressure required to operate a plurality of contact blades cannot exceed the force delivered by the return spring and since the return springs used in such switches are preferably small, it is another object of the present invention to provide a switch construction requiring low operating power yet secure reliable contact operation.

Also, since the plunger is desirably constructed of insulating material which is soft as compared to the metal switch blades actuated thereby, it is another object of the present invention to provide a construction in which plunger wear is minimized.

It is also another object of the present invention to provide a multiple pole switch in which the switches are generally enclosed to protect the same, yet access is provided without disturbing the assembly for the purpose of determining if operation is satisfactory and which will permit adjustment of the blades, if necessary.

Briefly, the objects of the present invention are accomplished by the provision of a two part molded insulated casing carrying the various electrical terminals and internally mounted identical switch blades with the rivets used for securing the various elements adapted to also serve as contacts. The casings are adapted to be facilely assembled either by rivets'or integrally formed self-locking members. A one piece molded plunger, adapted for reciprocating movement in a guideway formed by the two part casing, is provided with simple circumferential cam surfaces which permit the simultaneous actuation of respective pairs of spring blades in opposite directions either under their own spring tension or under the force exerted Patented May 10, 1966 by the plunger dependent on the direction of plunger movement and without unnecessary alignment problems. Surfaces are formed in the switch blades which also serve as plunger guideways, while cooperating with the plunger cam surfaces to secure eflicient application of force against the blades and good contact. An opening in the casing adjacent the free or movable end of each contact blade permits facile inspection. A stud is carried in an enlarged portion at one end of the guideway and it facilely permits the casings to be appropriately mounted and serves to hold the plunger return spring.

Other objects and features of this invention will become apparent upon further examination of the specification together with the drawings wherein:

FIG. 1 is a front elevational view of the switch assembly;

FIG. 2 is a side elevational view of the switch assembly;

FIG. 3 is a sectional View taken along the line 3-3 in FIG. 1;

FIG. 4 is a sectional view taken along the line 4-4 in FIG. 2;

FIG. 5 is a side elevational view of the one of the contact blades;

FIG. 6 is a top elevational view of the spring blade 7 shown in FIG. 5; and

FIG. 7 illustrates another arrangement for locking the two casings of the switch together.

In FIGS. 1 and 2 of the drawings a switch assembly is indicated therein by reference character It The switch assembly 10 comprises a left-hand casing 12 and a righthand casing 14 which are mirror images of each other. Each casing 12 and 14 is preferably of nylon and is provided with a corresponding matrix of recesses 16 arranged in aligned columns and rows with each recess 16 having an aperture therein for receipt of a rivet 18 in order to secure a respective terminal 20 in the respective recess. The terminals 20 are provided with linear edges co-acting with linear edges on the recesses 16 to prevent rotation of the terminals although held only by a single rivet. Extending fingers 22 are provided on each terminal to wrap around and clamp the uninsulated portion of and insulated portion of respective leads 24. Solder may also be used at the juncture. It will be noted that the orientation of the fingers 22 of each terminal on one casing 12 are oriented in an opposite direction from those on casing 14 in order to permit'facile spacing and grouping of the leads 24. The casings 14 and 12 are adapted to be clamped together by means of rivets 26 with the recesses 16 and terminals 20 in alignment with a respective recess and terminal on the other casing.

As seen in FIG..3 a plurality of integrally formed locating pins 28 may be provided on one face 29 of each casing member 12 and 14- intended to form the inner surface of the casing on completion of assembly 10. These are adapted to mate with corresponding aperture 30 on the other casing member for use in assembly of the casings. Also, as shown in FIG. 7, the rivets 26 may be omitted and a plurality of projections such as 31 with self-locking arrow like ends 32 may be integrally formed on each casing for engagement with a back 'wall 34 adjacent an aligned aperture 36 on the other casing.

As best seen in FIGS. 3 and 4 a plurality of vertically spaced recesses 38 are provided in the internal surface 29 of each casing member 12 and 14. Each internal recess 38 is aligned with a respective pair of horizontally aligned recesses 16 and is substantially coextensive with the respective pair of external recesses except that a passageway 40 may be provided at one end of each recess through the side wall of the'casing if desired. Each internal recess 38 is adapted to have one end of the associated pair of rivets 18 extending thereinto and is separated from the adjacent recess in the same casing by a rib portion 42. Thus aligned recesses in the casings 12 and 14 areadapted to form. respective cavities 44 when the casings 12 and 14 are assembled. A pair of switch blades 46 are located in each cavity with each blade being located in a respective recess 38.

One Switchblade 46 of each pair is riveted at one end to a respective one of the horizontally aligned pair of rivets 18 extending into the associated recess 38 with the riveted end of each blade 46 of the pair being at diagonally opposite corners of the respective cavity 44. Thus the 'free ends 48 of the blades are at diagonally opposite corners of the respective cavities and the free ends are provided with dished protuberances 50 formed by stamping. These protuberances t) serve as contacts to engage the ends of the other rivet 18 extending into the respective recess for extending electrical connections between the lead connected to that rivet and the lead connected to the riveted end of the blade 46. The blades 46 are normally tensed to disengage their free ends 48 from the respective rivets 18. These free ends may be seen through the respective optional passageways 40 indicated by broken lines if it is desired to provide visual inspection or if necessary adjustment.

Approximately midway between the ends of blades 46, as best seen in FIGS. 5 and 6, the blades are dished back along the vertical axis with a radius of approximately .1" to form a horizontally aligned crown 52 approximately .08 at its narrowest point with the vertical edges 53 of the dished portion curving away in opposite directions from the center of the crown. Thus, the crown provides a surface for actuating the spring blades 46 into engagement with the respective rivets 18 in response to the movement of a plunger 54 of insulating material without the plunger being scraped, cut or torn by the metal blades.

The plunger 54 is located in vertically aligned recesses 56 formed in the ribs 42 of each casing 12 and 14. The recesses 56 are adapted to cooperate with camming portions 58 and 60 on the plunger to act as guideways for the plunger 54. The camming portions 58 and 60' are enlarged cylindrical surfaces on the plunger approximately .139" diameter, which serve to move the free ends of the blades 46 into engagement with the rivets 18 when the portions 58 and 60- act against the crowns 52 of the respective blades.

It will be noted that recessed sections 62, 64 and 6 are provided on the plunger with the recessed sections 62 and 64 approximately .089" diameter lying between a respective pair of spring blades 46 in the center and lower end of the assembly so that those spring blades 46 are normally open. The enlarged portion 60 lies between the upper pair of blades 46 so that their contacts 50 are normally engaged with respective rivets 18. The

enlarged portions 58 and 66 are connected to the respective recessed portions 62, 64 and 66 by means of conically shaped bevels 68 which serves to smoothly cam theblades 46 in cooperation with edges 53 while the circular surfaces permit maximum distribution of wear. The upper bevel v68 normally seats against a shoulder 70 formed adjacent the upper end of the guideway and this shoulder '70 serves as a stop.

An enlarged recess 72 is provided in the upper end of each casing and the plunger extends therethrough. A threaded bushing 74 is located in the enlarged recess and a shoulder 76 on the bushing is located beneath a shoulder 78 on each casing to hold the bushing engaged in assembly 10 when the casings are assembled.

The bushing 74 enables the assembly 10 to be mounted in a door frame for example, while the plunger 54 protrudes from the casings under the bias of a spring 86 carried in the bushing 74 and engaged between a shoulder 82 on the bushing and a shoulder 84 adjacent the upper end of the plunger. This permits the plunger 54 to be actuated on closure of the door for example, with the spring 84 serving to return the plunger 54 when the door is opened. It will be appreciated of course that the plunger 54 may also be operated by other apparatus as well.

The blades 46 are arranged so that they are normally biased towards the plunger 54 under their own spring tension. This maintains the circuit open between one terminal 20 connected to each blade 46 and an adjacent terminal 20 connected to a rivet 18 with which the blade is adjusted to normally make contact. The center and lower switch blades 46 are normally disengaged from their respective rivets 18 to form break contacts since the respective recesses 62 and 64 on the plunger 54 are normally aligned with those switch blades. The upper set of blades have their free ends normally closed to respective rivets 18 under the influence of camming portion 60 to form break contacts.

When the plunger 54 is moved downwardly as seen in the drawings the enlarged cylindrical cam surface 58 is displaced from between the upper switch blades and a recessed portion 66 is brought into alignment therewith. The upper switch blades 46 therefore disconnect from the respective contacts under their own spring tension. The center and lower switch blades 46 are then separated by camming surfaces 60 and 58 respectively since the enlarged cam surfaces 60 and'58 are moved therebetween and these blades now open their respective contacts. It will be noted that cam surface 60 is long enough to maintain engagement with the respective guideway 56 while located either between the upper or center blades 46 and prevent misalignment of the plunger.

The foregoing is a description of an improved multiple pole switch whose inventive concepts are believed to be more fully set forth in the accompanying claims.

What is claimed is:

1. A switch comprising a pair of electrically insulated casing members each having a plurality of spaced apart horizontal recesses therein and an elongate vertical recess with the vertical recesses adapted to form a passageway on assembly of said members with each of said horizontal recesses in one member adapted to be aligned with a respective horizontal recess in the other member, a pair of rivets extending into each horizontal recess with one rivet of each pair located adjacent one side of the respective horizontal recess and the other rivet of each pair located adjacent the opposite side of the respective recess, a terminal for each rivet fastened external to the respective casing only by the respective rivet, a contact blade in each of said recesses with one end of each blade being held by one rivet of the respective pair and with the free end of each blade located adjacent the other rivet of the pair and normally adapted to be disengaged therefrom, the other rivet in each pair of aligned horizontal recesses being located adjacent diagonally opposite sides of the respective recesses, a plunger aligned in said passageway and adapted to be actuated by a mechanism located external to said casings, a cylindrical cam surface on said plunger adapted to guide said plunger in said passageway and arranged between one pair of said aligned horizontal recesses for holding the free end of each blade in said one pair of horizontal recesses engaged with a respective other rivet, said plunger having a recessed portion on opposite sides of said cam surface with one of the recessed portions adapted to be aligned with another pair of said blades for enabling the free end of said other pair of blades to separate from the respective other rivets whereby movement of said plunger in one direction aligns said cam surface with said other pair of said blades to cause the other blades to engage the respective other rivets while the other recessed portion enables said one pair of blades to separate from the respective other rivets.

2. A switch comprising a pair of electrically insulated casing members each having a plurality of spaced apart horizontal recesses therein and an elongate vertical recess with the vertical recesses adapted to form a passageway on assembly of said members with each of said horizontal recesses in one member adapted to be aligned with a respective horizontal recess in the other member, a pair of rivets extending into each horizontal recess with one rivet of each pair located adjacent one side of the respective horizontal recess and the other rivet of each pair located adjacent the opposite side of the respective recess, a terminal for each rivet fastened external to the respective casing by the respective rivet, a contact blade in each of said recesses with one end of each blade being held by one rivet of the respective pair and with the free end of each blade located adjacent the other rivet of the pair and normally adapted to be disengaged therefrom, a plunger aligned with said passageway and adapted to be actuated by a mechanism located external to said casings, and a cylindrical cam surface on said plunger cooperating with said passageway to guide said plunger in said passageway and arranged between one pair of said alig'ned horizontal recesses for holding the free end of each blade in said one pair of horizontal recesses engaged with a respective other rivet, said plunger having a recessed portion adapted to be aligned with said pair of said blades for enabling the free end of each of said blades to separate from the respec tive other rivets whereby movement of said plunger in one direction aligns said cam surface with another pair of said blades to cause the other blades to engage the respective other rivets while said recessed portion enables said one pair of blades to separate from the respective other rivets.

3. The switch claimed in claim 2 in which said recessed portion is cylindrical, and a conical portion is provided on said plunger between said cam surface and said recessed portion for wedging action against said one pair of springs in response to movement of said plunger in the other direction.

4. A switch comprising a pair of electrically insulated casing members each having a plurality of spaced apart horizontal recesses therein and an elongate vertical recess with the vertical recesses adapted to form a passageway on assembly of said members with each of said horizontal recesses in one member adapted to be aligned with a respective horizontal recess in the other member, a plunger in said guideway, a pair of rivets extending into each horizontal recess with one rivet of each pair located adjacent one side of the respective horizontal recess and the other rivet of each pair located adjacent the opposite side of the respective recess, a contact blade in each of said recesses with one end of each blade being held by one rivet of the respective pair and with the free end of each blade located adjacent the other rivet of the pair and normally adapted to be disengaged therefrom, a plunger aligned in said passageway and adapted to be actuated by a mechanism located outside said casings, a cylindrical cam surface on said plunger adapted to guide said plunger in said passageway and arranged between one pair of said aligned horizontal recesses for holding the free end of each blade in said one pair of horizontal recesses engaged with a respective other rivet, said plunger having a recessed portion arranged between another pair of said blades for enabling the free end of said other blades to separate from the respective other rivets and a conical portion on said plunger interconnecting said recessed portion and cam surface for wedging action against said other pair of blades on movement of said plunger in one direction to align said cam surface with said other pair of said blades and cause the other blades to engage the respective other rivets.

5. In the switch claimed in claim 4 a horizontal crowned section on each blade for smoothly engaging said conical portion and cam surface with the vertical edges of said crowned section curving from the axis of said plunger.

6. A switch comprising a pair of electrically insulated body elements each having a plurality of spaced apart horizontal recesses therein, an elongate vertical passageway adapted to be formed on assembly of said elements with each of said horizontal recesses being aligned with a respective other horizontal recess, a plunger in said guideway, a contact blade in each of said recesses with the pair of contact blades in a pair of aligned horizontal recesses being spaced apart from another. pair of switch blades and from each other, a contact in each recess for the respective blade and adapted to be normally disengaged from the blade under the spring tension of the blade, a return spring encircling said plunger and adapted to bias said plunger in one direction, a cam surface on said plunger for holding one pair of said blades in engagement with the respective contacts and a recessed portion on said plunger adapted to be aligned with said engaged pair of blades on movement of said plunger in the opposite direction for permitting said blades to disengage from said contacts while said cam surface engages another pair of blades to engage said other blades with their respective contacts.

7. A switch comprising a pair of electrically insulated casing members each having a plurality of spaced apart horizontal recesses therein and an elongate vertical recess with the vertical recesses adapted to form a passageway on assembly of said members and with each of said horizontal recesses adapted to be aligned with respective horizontal recess in the other member, a plunger in said guideway, a contact blade in each of said horizontal recesses with one end of each contact blade riveted to a respective one of said casings and to an electrical terminal on the exterior of said one casing, the other end of each blade being free and located adjacent the riveted end of the blade in the respective aligned recess, the free end of each blade adapted to engage a respective other rivet carrying a terminal on the exterior of the respective one of said casings when the blade is operated in one direction, a bushing carried between said casings for mounting said casings with said plunger extended through said bushing and external thereto whereby said plunger may be actuated by a mechanism located outside said casing, a return spring carried in said bushing for biasing said plunger in one direction, a cylindrical cam surface on said plunger for holding one pair of said spring blades in engagement with respective one of said rivets forming a contact, said plunger having a recessed portion adapted to be aligned with another pair of said blades for enabling said blades to separate from a respective one of said other rivets whereby movement of said plunger in one direction disengages said cam surface with said one pair of said blades while said plunger recessed portion enables said one pair of blades to separate from the respective other rivets.

8. A switch comprising a pair of electrically insulated casing members each having. a plurality of spaced apart horizontal recesses therein and an elongate vertical recess with the vertical recesses adapted to form a passageway or assembly of said housings and said horizontal recesses adapted to be aligned with a respective recess in the other member, self-locking means carried by said casings and integrally formed on a respective casing for locking said casings into engagement on assembly thereof, a plunger in said guideway, a switch blade in each of said recesses with one switch blade being riveted at one end to a respective one of said casings and an electrical terminal on the exterior of said casing, a contact for each switch blade adapted to be engaged by the respective switch blade when operated in one direction, a return spring for biasing said plunger in one direction, and a cylindrical cam surface on said plunger for holding one pair of said spring blades in engagement with respective ones of said contacts while serving to guide said plunger in said guideway, said plunger having a recessed portion aligned with another pair of said spring blades for enabling said other spring blades to separate from the respective contacts whereby movement of said plunger in one direction aligns said cam surface with said other pair of said spring blades to operate said other blades in said one direction to cause said other blades to engage the respective contacts while said cam surface disengages from the one pair of spring blades to enable said spring blades to operate in the other direction and separate from their respective contacts.

9. The switch claimed in claim 8 in which said casings are adapted to form either a complete enclosure for said blades or are adapted to be provided with openings for permitting inspection of said blades.

No references cited.

KATHLEEN H. CLAFFY, Primary Examiner.

H. I-IOHAUSER, Assistant Examiner. 

6. A SWITCH COMPRISING A PAIR OF ELECTRICALLY INSULATED BODY ELEMENTS EACH HAVING A PLURALITY OF SPACED APART HORIZONTAL RECESSES THEREIN, AN ELOGNGATE VERTICAL PASSAGEWAY ADAPTED TO BE FORMED ON ASSEMBLY OF SAID ELEMENTS WITH EACH OF SAID HORIZONTAL RECESSES BEING ALIGNED WITH A RESPECTIVE OTHER HORIZONTAL RECESS, A PLUNGER IN SAID GUIDEWAY, A CONTACT BLADE IN EACH OF SAID RECESSES WITH THE PAIR OF CONTACT BLADES IN A PAIR OF ALIGNED HORIZONTAL RECESSES BEING SPACED APART FROM ANOTHER PAIR OF SWITCH BLADES AND FROM EACH OTHER, A CONTACT IN EACH RECESS FOR THE RESPECTIVE BLADE AND ADAPTED TO BE NORMALLY DISENGAGED FROM THE BLADE UNDER THE SPRING TENSION OF THE BLADE, A RETURN SPRING ENCIRCLING SAID PLUNGER AND ADAPTED TO BIAS SAID PLUNGER IN ONE DIRECTION, A CAM SURFACE ON SAID PLUNGER FOR HOLDING ONE PAIR OF SAID BLADES IN ENGAGEMENT WITH THE RESPECTIVE CONTACTS AND A RECESSED PORTION ON SAID PLUNGER ADAPTED TO BE ALIGNED WITH SAID ENGAGED PAIR OF BLADES ON MOVEMENT OF SAID PLUNGER IN THE OPPOSITE DIRECTION FOR PERMITTING SAID BLADES TO DISENGAGE FROM SAID CONTACTS WHILE SAID CAM SURFACE ENGAGES ANOTHER PAIR OF BLADES TO ENGAGE SAID OTHER BLADES WITH THEIR RESPECTIVE CONTACTS. 